1. Field of the Invention
The present invention relates to the field of medical research devices, and more particularly, to a magnetically aligned electrical connector assembly for use with a neural monitoring device in experiments on live animals.
2. Description of the Related Art
There are numerous examples of electrical connectors that employ magnetic components to assist in the alignment or attachment of electrical connections that are the subject of issued patents, but none of these inventions includes the novel features and advantages of the connector of the present invention. The present invention provides for an easy and reliable connection to be made between the two halves of a subminiature, high-density surface-mount connector by persons having very little prior training. The user is not required to make an accurate visual alignment of the electrical pins during the connection process because magnetic force provides precise alignment of the pins when the user brings the two halves of the connector into approximately alignment.
U.S. Pat. No. 4,004,298 (Freed, 1977) discloses a magnetically aligned connector for a heart-assist apparatus, wherein the separation force to disconnect the two halves of the connector is less than the pulling force that will cause injury to the patient. In a preferred embodiment, the connector is used to connect one electrical signal and one source of compressed air. Although magnets are used to obtain proper alignment of the two connector halves during the connection procedure, a mechanical interlock is used to positively lock the two parts together during use. The magnets, which are in direct contact, serve as the electrical contacts. In one embodiment (FIG. 2), three magnets in the top half align with three magnets in the bottom half, with magnet polarization set so as to cause the two halves to align in only one orientation.
U.S. Pat. No. 4,025,964 (Owens, 1977) discloses an electrical connector for connecting wires within the body of a human medical patient to external wiring. The connector is comprised of a socket and a complimentary shaped plug. The plug is held in the socket by the magnetic force between a magnet located in the socket and magnetic material located in the plug. The electrical contacts consist of inclined conductive strips on the plug assembly that wedge against mating inclined conductive strips on the socket assembly. The device is described as being suitable for connecting two or three different conductor wires.
U.S. Pat. No. 4,067,342 (Burton, 1978) discloses a flexible electrode device capable of transmitting electrical signals through human skin. The device is comprised of flexible, electrically conductive adhesive tape. External wires are connected to the tape via magnetic particles on the wire connector that magnetically couple with magnetic particles bonded to the tape. The magnetic particles, which are in direct contact, serve as the electrical contacts.
U.S. Pat. No. 4,112,941 (Larimore, 1978) discloses a biomedical electrode for providing a removable and rotatable electrical connection to the skin of a medical patient. The device consists of an electrode component attached to the skin and a connector component with external wires. Magnetic force is used to hold the electrode and connector components in electrical contact. The electrode component comprises a magnetic plate and a raised post. The connector component comprises a magnetic ring with a center hole. When the two components are held together by magnetic force, the post of the electrode fits into the specially shaped hole of the connector, so that the post and the inside walls of the hole are always in electrical contact. The device comprises a single electrical conductor.
U.S. Pat. No, 4,211,456 (Sears, 1980) discloses a magnetically connected electrical connector, wherein the connector component of the device comprises a spherically shaped ferrous metal male connector that attaches to a female component via magnetic force provided by a permanent magnet located within the female component. The device provides a single electrical connection for each male-female pair of components.
U.S. Pat. No. 4,259,065 (Fukuda et. al., 1981) discloses an electrode device for connecting electrical monitoring equipment to the skin of a medical patient. The device comprises a base component that attaches to the skin of a medical patient and a terminal component that may be removably attached to the base component by magnetic force. The terminal component comprises a disc-shaped magnet that attaches magnetically to a disc-shaped ferro-magnetic element within the base unit. The electrical contacts are the magnet and the ferromagnetic material. The device provides a single electrical connection for each magnet-ferro magnetic material pair.
U.S. Pat. No. 4,653,503 (Heath, 1987) discloses a physiological electrode that is designed to be attached to the body of a medical patient. The device comprises a magnetic coupler that removably attaches a lead wire assembly to the electrode assembly, which is mounted on the patient's skin. The lead wire assembly comprises a permanent magnet, and the electrode assembly comprises a matching ferro-magnetic member, which is attracted by magnetic force to the magnet, thereby holding the lead wire assembly in contact with the electrode assembly. In this device, the electrical contacts are provided by the magnet and ferro-magnetic material, and there is a single electrical connection for each magnet-ferro magnetic material pair. The electrode assembly may optionally comprise a raised lip to help prevent accidental release of the lead wire assembly.
U.S. Pat. No. 4,947,846 (Kitagawa et al., 1990) discloses a waterproof electrode device that is designed to be attached to the skin of a medical patient. The device comprises an electrode component that attaches to a medical patent's skin and a removable wire lead connector that is magnetically attached to the electrode component. The magnetic attachment force is provided by a permanent magnet within either the electrode component or the connector component and either a magnet or magnetic material within the other component. The electrical connection is made waterproof by a closed-cell foam seal between the two components. The electrical contacts are provided by a conductive yoke in the connector component that contacts the magnetic material of the electrode component. This device provides a single electrical connection for each magnet-magnet pair or magnet-magnetic material pair.
U.S. Pat. No. 7,359,744 (Lee et. al., 2008) discloses an electrical bio-potential sensor (electrode) that connects to a medical patient's skin via short needles that penetrate into the upper layer of skin. Electrical signals from the needles are conducted via electrical contacts to a removable wireless transmitter that is mounted on top of the electrode component. The electrical contacts on the electrode component and transmitter component are held together by magnetic force that is provided by a plurality of magnets on the electrode component that attach to a plurality of matching magnets that are mounted on the transmitter component. The details of the electrical contacts are not disclosed. The example device described in the patent document comprised four magnet pairs and three electrical connections.
U.S. Pat. No. 7,473,145 (Ehr et al., 2009) and U.S. Pat. No. 7,772,412 (Ehr et. al., 2010) disclose several embodiments of a removable and reusable electrode connector component. In some embodiments (shown in FIGS. 7 through 10), the connector wire is attached to a flat, electrically conductive magnet, and this magnet attaches to a magnetic electrode pad having an electrically conductive zone that provides an electrical connection from the electrode to the connector wire. These devices comprise one electrical connector for each magnet pair.
U.S. Pat. No. 7,068,580 (Shin et al., 2010) and U.S. Pat. No. 8,214,009 (Shin et al., 2012) disclose several embodiments of an electrode and an analog-to-digital signal processing member. In one embodiment (FIG. 11), the electrical contacts of the electrode component and the signal processing unit may alternately be “mechanically combined with each other using magnetism and a magnetic substance.” No further details of the magnetic components are disclosed.
U.S. Pat. No. 8,332,009 (McLaughlin et al., 2012) discloses a two-part sensor unit for medical patents comprising a sensing component mounted on the patient's skin and a receiving component that transmits the signals wirelessly. The two components are electrically and magnetically connected by a connector unit that comprises a magnet stud and a magnetizable stud, with a magnetic female clip in between the two studs. The device comprises one magnet assembly for each electrical conductor.
U.S. Pat. No. 8,388,353 (Kiani et al., 2013) discloses a magnetic connector comprising a receptacle component and a plug component. FIG. 5B shows a 42-contact connector. In some embodiments, an electromagnet is used to provide magnetic force to join the two components, thereby causing electrical contact between an array of electrical pins and sockets in the two components. In other embodiments, a permanent magnet is used to provide magnetic force that pulls the two components together, while actuating an electromagnet overcomes the attractive force of the permanent magnet and pushes the two components apart. The device comprises an array of electrical contacts and a single permanent magnet for embodiments that incorporate a permanent magnet. There is no other detail disclosed regarding alignment.
U.S. Pat. No. 8,408,948 (Selvitelli et al., 2013) discloses several embodiments of electrocardiograph (ECG) electrode connectors. These devices comprise a spring member as a component of the mechanical locking mechanism of the various embodiments, wherein the locking mechanisms use cams or other methods to firmly and removably grasp an electrode wire. Although magnets are not depicted or specifically described in the various embodiments, the description (column 3, lines 50-55) states: “It should be understood that the spring members disclosed herein are not limited to coil and/or leaf springs, and may include any suitable source of biasing force, including without limitation gas springs, pressure- or vacuum-actuated devices, elastomeric springs, magnetic or electromagnetic devices . . . ”
U.S. Pat. No. 3,786,391 (Mathhauser, 1974) discloses a magnetic self-aligning electrical connector. This device comprises a nominally round male coupling half and a nominally round female coupling half, with a plurality of male electrical connectors mounted around a central magnet in the male half, and a matching plurality of female electrical connectors mounted around a central piece of ferro-magnetic material. The male connectors are cylindrical with tapered points, and the female sockets are cylindrical with tapered bottoms. When the two halves of the device are placed in close proximity, the attractive magnetic force between the magnet and the ferro-magnetic material causes the male pins to seat into the female sockets, with the tapered portions of the pins and sockets making electrical contact. The description does not specifically state if the magnet and ferro-magnetic material are in direct contact when the two halves of the device are electrically connected.